Optimal hybrid PV-PTC integration with existing hydropower for reliable and cost-effective energy supply

Abstract This study investigates the integration of existing hydropower with photovoltaic (PV), parabolic trough collector (PTC), and hybrid PV-PTC systems to achieve zero loss of power supply probability (LPSP), minimum levelized cost of energy (LCOE), and near-complete hydropower utilization (remaining ≤ 0.05%). An 8760-hour simulation and coarse-to-fine parametric optimization framework are employed to evaluate system reliability, renewable-energy utilization, curtailment, and economic performance. The PV-based system requires 177.48 MW, utilizes 289.90 GWh of PV energy, exhibits 7.88% curtailment, and achieves an LCOE of 0.090576 $/kWh. The PTC-based system requires 143.36 MW, utilizes 289.96 GWh, reduces curtailment to 4.05%, and achieves an LCOE of 0.087199 $/kWh. The optimal hybrid configuration comprises 52,000 PV units (12.43 MW) and 724 PTC units (131.88 MW), achieving zero unmet load and utilizing 696.160178 GWh of hydropower with only 0.00026% remaining. It supplies 22.05 GWh from PV with zero curtailment and 267.85 GWh from PTC with 3.66% PTC curtailment, while achieving the lowest baseline LCOE of 0.087156 $/kWh. Sensitivity analysis shows that the economic advantage over the PTC-only system is marginal and dependent mainly on PV and PTC investment costs. Overall, the hybrid configuration provides the most balanced technical performance through high reliability, reduced renewable curtailment, and effective utilization of the existing hydropower resource.